The field of the invention is that of hermetic compressors installed in appliances such as refrigerators, freezers, air conditioners, dehumidifiers, and the like. More particularly, the field is that of apparatus for mounting a compressor to an appliance frame, enclosure, or cabinet.
Hermetic compressors comprise a motor-compressor unit disposed within a hermetically sealed outer housing. An electrical connection is made via a terminal which extends through a sidewall of the housing, while fluid conduits extend through the sidewall to provide an external connection for the refrigerant fluids. The hermetic compressor is easily incorporated into an appliance by mounting the compressor to the appliance cabinet and making the appropriate electrical and fluid connections. However, compressors generate undesired noise and vibration which can only be reduced by mounting the compressor in a manner which suppresses the undesired noise and vibrations.
Various structures are used to mount a hermetic rotary compressor in an appliance cabinet, typically upon a horizontal surface in an upright position. One structure has a base plate welded to the bottom of the compressor housing, with the base plate having a plurality of holes that have grommets forcibly fit into them. The grommets have apertures with sleeves through which a nut and bolt assembly is received to secure the compressor and plate to the appliance. Another structure involves welding, to the bottom of the compressor housing, a plurality of support legs which are shaped and positioned to be placed upon posts which are interposed between the legs and the horizontal support surface, the posts having a pad or other resilient material to absorb noise and vibration.
The previously mentioned structures require the mounting apparatus to be welded onto the compressor housing. Welding increases the manufacturing cost and subjects the housing to heat which may result in undesired deformation of the housing. Additionally, the extra components (the plate and legs) increase the complexity, hence the chance of error during assembly.
Another type of structure involves supporting the compressor on a resilient material which separates the compressor from the horizontal support surface. One such structure comprises a plurality of hollow spring cylinders which engage locations on the bottom of the compressor housing, with the compressor resting on the springs. However, this structure requires that the compressor be supported at its top end to insure vertical stability, typically by welding a mounting stud to the compressor housing and providing additional support structure on the appliance cabinet.
Further prior art structure includes a circular resilient grommet of chloroprene rubber formed with an upstanding annular flange to engage the bottom of a compressor. The compressor is secured against movement by an elaborate mounting arrangement, thus requiring a plurality of components and assembling them which increases the complexity and cost.
Another prior art mounting structure is disclosed in U.S. Pat. No. 4,461,446 (Hannibal). A plurality of indentations are located on the underside of the compressor housing for receiving grommets. The grommets may be of resilient material so that barbs or other projections on the base surface become embedded in the grommets when the compressor is lowered onto the surface. Although an improvement over previous devices, the Hannibal mounting device still requires additional manufacturing steps to make the projections, to place the grommets on the projections, and to position the compressor so the grommets are within the indentations. Also, this device requires a modification of the compressor housing design to accommodate the indentations.
While these prior art structures serve to attach a compressor to an appliance cabinet, problems exist. The compressor imparts undesired vibration to the supporting base as well as causing noise to radiate from the compressor housing. The noise and vibration are readily transmitted from the compressor mechanism by an end plate which typically forms one end of the compressor housing. These problems are particularly pronounced with compressors having an end plate adjacent to the cylinder block of a rotary vane compressor mechanism because noise tends to radiate from the end plate.
Thus, what is needed is a mounting structure for attaching a compressor to a horizontal support surface in a vertical position with minimal additional structure on the compressor housing and appliance cabinet, so that vibration and noise radiating from the compressor housing are suppressed.